04/02/2012 10:17 am ET

Hilary Duff Hits The Gym Two Weeks After Giving Birth

New mom Hilary Duff is already back at the gym, just a week and a half after giving birth.

The 24-year-old singer and actress welcomed her first child with husband Mike Comrie on March 20 and Hilary is already trying to get her pre-baby body back -- but it's not easy.

"20 minutes on the elliptical seems like an eternity!!! What the hell...." Duff tweeted on Saturday.

Duff is trying to get back to her old self and last week was spotted outside for the first time since giving birth. On Thursday, the actress was spotted wearing leopard-print skinny jeans en route to the hair salon. Afterward, she tweeted a photo of her freshly colored hair and gave a shout-out to her stylist on Twitter: "Just got my hair did from my girl Riawna Capri, thanks love! I'm feeling fresh! Heading back home to hang with munchkin :)"

Duff has joined the ever-growing group of young moms in Hollywood and she has been quick to admit that this whole new parenting thing isn't easy. The actress has been sharing her milestones with her fans on Twitter.

Last week she wrote, "1st outing complete with no tears!Made it home early...just in time to feed Luca.figuring this motherhood thing out!Yay! A grown up din;)"

The former "Lizzie McGuire" star is slowly getting used to her new role as a mom, which of course includes 4 a.m. feedings.

"Luca fed! Mamma fed! Time to do it all again in 2 hours! Oh how life has changed! Lol In such a wonderful way :)," she tweeted, later adding, "4 am...Sleepy eyed. Feeding baby..whew this job is no joke!"

Check out photos of other stars who are expecting babies this year:

Celebrity Babies On The Way